Freight containers

ABSTRACT

A freight container of generally cuboidal shape includes a pair of sides which define lateral extremities of the container and extend between ends of the container. The exterior surfaces of the pair of sides are spaced apart by a greater distance along their middle portions than along their end portions which are joined to the ends of the container, whereby the overall exterior width of the container is less at the end portions than at the middle portions. The internal width measured between the middle portions of the sides is more than 2400 mm but the overall thickness of each of the middle portions of the sides is less than 25 mm and the overall exterior width measured at the middle portions of the sides is less than 2470 mm. The container therefore has increased capacity for a given size of each end and is able to be located side-by-side with conventional container.

This invention relates to freight containers. Such containersconventionally have a respective corner fitting at each corner by meansof which the containers can both be engaged by container handlingapparatus when being loaded or unloaded from a wheeled vehicle or shipand be held in position on such a vehicle or ship.

In EP 0 206 542, a freight container is described that is of generallycuboidal shape including a pair of sides which define the lateralextremities of the container. Exterior surfaces of the pair of sides arespaced apart by a greater distance along their middle portions thanalong their end portions whereby the overall width of the container isless at the end portions than at the middle portions. With a freightcontainer according to EP 0 206 542 the spacing of the end portions ofthe sides can be made such that the ends of the container can just befitted between the cell guides of a container ship, while away from thecell guides the sides are spaced further apart and the internal width ofthe container can be increased. It is suggested that the difference inspacing between the middle and end portions may be in the range of 20 to100 mm.

In a particular example of a container described and shown in EP 0 206542 the exterior surfaces of the pair of sides are spaced apart at theirends by 2438 mm and, at their middle portions by 2500 mm allowing for aninternal width of 2444 mm. Such an internal width is adequate toaccommodate two metric pallets of standard size, namely 1.2 m×1.0 m,side-by-side with their major dimensions (1.2 m) extending across thecontainer. Although notionally an internal width of 2400 mm would enabletwo metric pallets to be accommodated across the width in the same way,that is not feasible in practice because of tolerances andirregularities in the packing of goods on the pallets.

A container in accordance with EP 0 206 542 has proved very successfulin practice because in terms of its load carrying capacity it iscomparable to a container of 2500 mm overall width, yet it is able tofit in cell guides in a ship that are positioned for containers of 2438mm width. There are, however, some occasions where the increased widthof the container is a disadvantage, as will now be described. One commonconventional form of container has an overall width of 2438 mm and onoccasions arrangements are made to locate such containers side-by-sidewithout leaving any space for cell guides or the like; in that case, ofcourse, there is a problem if the container is as described above andhas a maximum width of 2500 mm rather than 2438 mm. If the maximum widthwere reduced from 2500 mm to 2438 mm in order to try to solve thatproblem, then the correspondingly reduced internal width would be wellbelow that needed to accommodate two metric pallets side-by-side withtheir major dimensions extending across the container.

It is an object of the invention to provide a container which overcomesor mitigates the disadvantage referred to above of the container shownand described in EP 0 206 542.

According to the invention there is provided a freight container ofgenerally cuboidal shape including a pair of sides which define lateralextremities of the container and extend between ends of the container,the exterior surfaces of the pair of sides being spaced apart by agreater distance along their middle portions than along their endportions which are joined to the ends of the container, whereby theoverall exterior width of the container is less at the end portions thanat the middle portions of the sides, wherein the internal width measuredbetween the middle portions of the sides is more than 2400 mm but theoverall thickness of each of the middle portions of the sides is lessthan 25 mm and the overall exterior width measured at the middleportions of the sides is less than 2470 mm.

The use of such an unusually thin wall to form the middle portion ofeach side of the container, combined with the appreciation of certainother matters, makes it possible to overcome the problem referred toabove, as will be explained below.

Preferably the thickness of each of the middle portions of the sides isabout 20 mm. Although that is an exceptionally small thickness for aside wall of a freight container it could be expected that such athickness still would not enable the problem to be overcome becauseeither the overall exterior width would be too great or the internalwidth would be too small. That is especially the case since in practicethe internal width measured between the middle portions of the sides ispreferably more than 10 mm greater than 2400 mm and, more preferably, is2419 mm±5 mm (i.e. in the range from 2414 mm to 2424 mm). It can readilybe seen that with such an internal width and a thickness of each of thetwo middle portions of the sides of 20 mm, the overall exterior widthmeasured at the middle portions of the sides will be about 2460 mm.Preferably, the overall exterior width is 2462 mm±5 mm (i.e. in therange from 2457 mm to 2467 mm). Such an exterior width is of coursegreater than the width of 2438 mm of a standard conventional containerbut we have found that such an increased width does not affectsignificantly the places in which the container can be put. The increasein width in the case of a container of 2462 mm overall exterior width asagainst a container of 2438 mm overall exterior width is only 12 mm oneach side of the container. In the container industry such a smalldiscrepancy will not generally give rise to any significant problems andthere will often be an allowance made anyway for variations in theactual widths of containers from the nominal width of 2438 mm. Thus, forexample, containers having an overall exterior width of 2462 mm willusually be able to be placed in spaces intended for standardconventional containers of overall exterior width 2438 mm.

Thus it will be seen that by careful choice of dimensions for theinternal and overall exterior widths and by providing a container inwhich the overall thickness of each of the middle portions of the sidesis relatively small, it is possible to provide a container which on theone hand is able to accommodate two metric pallets of standard size,namely 1.2 m×1.0 m, side-by-side with their major dimensions (1.2 m)extending across the container and on the other hand is able to beplaced in all, or almost all, spaces intended for containers of standardconventional overall width of 2438 mm.

In principle, various different structural arrangements for the middleportions of the sides of the container could be used to provide theunusually thin side wall. It is, however, most preferable that thestructure of the side wall can be made relatively cheaply. Preferablythe middle portion of each side comprises a bottom rail member, aplatform member fixed to the top of the bottom rail member and defininga substantially horizontal surface on top of the bottom rail member, andcorrugated panelling the corrugated bottom of which is secured to thesubstantially horizontal surface defined on top of the bottom railmember. Providing a platform member that is formed separately from thebottom rail member makes it possible to provide a wider substantiallyhorizontal surface to which the corrugated panelling can be secured.Indeed with such an arrangement the substantially horizontal surface mayextend across the entire thickness of the middle portion of the side. Ifa top portion of the bottom rail member were simply folded to form thehorizontal surface, then as a result of the relatively large radius ofcurvature of the bend the horizontal surface would inevitably not extendacross the entire thickness of the middle portion of the side and thethickness of that portion would have to be increased to provide the samewidth of horizontal surface.

The platform member is preferably of inverted, substantially "L" shapewith one limb extending downwardly adjacent to the top of the bottomrail member and the other limb extending substantially horizontally. Insuch a case, the downwardly extending limb can be positioned alongsidethe top of the bottom rail member and welded securely thereto.

It is advantageous for inner surfaces of the bottom rail member to bespaced apart by the minimum internal width of the container since theyare then able to act as guides and buffers for pallets being loaded intothe container. Accordingly, it is advantageous for the limb of theL-shaped member that extends substantially horizontally to extendoutwardly from the other downwardly extending limb.

The platform member is preferably formed in an "L" shape by hot rolling.Pre-forming the platform member in an "L" shape is preferable to bendingthe member into the "L" shape because it is possible to avoid a largeradius of curvature on the outside of the "L" where the two limbs meet.

Preferably at least one longitudinally extending rib is formed in thebottom rail member. Such a rib is able to stiffen the bottom railmember. As already indicated, the bottom rail member is preferably atthe inner extremity of the side of the container and therefore thelongitudinally extending rib preferably extends outwardly from thebottom rail member.

Ribs extending parallel to the corrugations are preferably provided inthe corrugated panelling. Because of the unusually thin wall, theamplitude of the corrugations is unusually small and the provision ofribs extending parallel to the corrugations serves to add stiffness tothe corrugated panelling. The ribs in the corrugations are much lessdeep than the corrugations themselves and are preferably containedwithin the volume defined by the other parts of the corrugatedpanelling.

By way of example, an embodiment of the invention will now be describedwith reference to the accompanying drawings, of which:

FIG. 1 is a side view of a freight container,

FIG. 2 is an end view of a door end of the container,

FIG. 3 is a sectional view along the lines III--III of FIG. 1 throughone side of the container,

FIG. 4 is an enlarged sectional view of part of the side wall shown inFIG. 3, and

FIG. 5 is a sectional view along the lines V--V of FIG. 1 through oneside of the container.

The freight container shown in the drawings is of generally cuboidalshape having ends 1, 2, sides 3, a top 4 and a bottom 5. The end 1 ofthe container is provided with a pair of double doors 6 mounted on hingeposts 7 (FIG. 3). The container is substantially symmetrical about avertical plane containing the longitudinal axis of the container. Cornerfittings 39 are provided at each corner of the container.

The drawings omit various details of the container in the interests ofclarity and that is especially the case in FIGS. 1 to 3. The structureof most of the container is of a kind known per se and will not bedescribed further here. The construction of each side of the containeris, however, special and will be described below.

As can be seen clearly in FIG. 3, the exterior surfaces of the sides ofthe freight container are spaced apart by a greater distance along theirmiddle portions 10 that are corrugated than along their end portions 11that are not corrugated. Formed as integral extensions of the endportions 11 are interconnecting portions 12 that are inclined at anacute angle to the longitudinal axis of the container and connect themiddle portions 10 to the end portions 11.

Referring now to FIG. 5, each side 3 at a middle portion comprises abottom rail member 15, a platform member 16 fixed to the top 17 of thebottom rail member and defining a substantially horizontal surface 18 ontop of the bottom rail member, and corrugated panelling 19, thecorrugated bottom of which is secured to the substantially horizontalsurface 18 defined on top of the bottom rail member 15. A flat bar 20 isfixed to the top of the corrugated panelling 19 and a roof 21 is in turnfixed to the flat bar. The platform member 16 is of inverted,substantially "L" shape with one limb 22 extending downwardly alongsidethe top 17 of the bottom rail member 15 and the other limb 23 extendingsubstantially horizontally outwardly. The top 17 of the bottom railmember 15 is displaced outwardly by a crank 24 formed therein, forexample by bending or pressing, to allow the downwardly extending limb22 of the platform member 16 to lie inside and alongside the top 17 ofthe bottom rail member 15 without projecting into the interior of thecontainer any further than other parts of the bottom rail member. Theplatform member 16 is formed in a "L" shape by hot rolling. In theparticular example of the invention illustrated, the downwardlyextending limb 22 of the platform member 16 is longer than thehorizontally extending limb 23.

The corrugated panelling 19 has its interior boundary face 34 co-planarwith the interior face 25 of the bottom rail member 15 and has anoverall thickness slightly less than the width of the horizontal surface18 defined by the platform member 16. Accordingly, there is a smallspace left on the outside of the surface 18 of the platform member 16beyond the corrugated panelling and that enables the panelling 19 to bewelded at W1 to the platform member 16 on the outside along the entirelength of the panelling. A continuous weld W2 is also provided on theoutside of the container between the bottom rail member 15 and theplatform member 16 and a stitch weld W3 is provided on the inside of thecontainer between the bottom of the platform member 16 and the bottomrail member 15.

The bottom rail member 15 has a rib 26 extending along the containerwhich serves to stiffen the rail member. The rib 26 is formed by bendingor pressing the bottom rail member to the desired shape.

Also shown in FIG. 5 is the container floor 27 which rests on aninwardly projecting portion 28 of the bottom rail member 15.

It should be noted in FIG. 5 that only the extreme top and bottomportions of the corrugated panelling 19 are shown. The bottom railoccupies only a very small proportion of the overall height of thecontainer.

Referring especially to FIG. 4 it will be seen that corrugated panelling19 has corrugations that run vertically and comprises portions 29sharply inclined to the longitudinal axis of the container, innerportions 30 and outer portions 31 which are parallel to the longitudinalaxis of the container. Midway along each portion 30 and 31 a respectivevertical rib 32 is provided. The rib 32 on an inner portion 30 projectsoutwardly whilst a rib 32 on an outer portion 31 projects inwardly sothat the ribs are contained within the volume defined between theportions 30 and 31 of the corrugated panelling. As shown in FIG. 4 thedepth of each rib 32 is much less than the overall thickness of thepanelling. The ribs 32 add further strength to the panelling 19.

The bottom rail members 15 extend substantially the whole length of thecontainer and thus extend into the end portions 11 of the container. Theexterior width between the extremities of the bottom rail members 15(i.e. the spacing between the extremities of the ribs 26) is constantalong their length and is arranged to correspond to the spacing of theexterior surfaces of the sides of the container at their end portions.The corrugated panelling 19 terminates at the junction of theinterconnecting portions 12 and the middle portions 10 of the containerare welded to the inner surfaces of the interconnecting portions 12. Theplatform members 16 extend to the junction of the interconnectingportions 12 and the end portions 11, but each horizontally extendinglimb 23 of each platform member 16 reduces progressively in width alongthe length of the respective interconnecting portion 12 towards therespective end portion 11 so that the limb 23 does not project laterallyunduly beyond the interconnecting portion 12 yet provides a platform forthat portion.

In one particular example of the invention, the principal dimensions ofthe container are as follows:

    ______________________________________                                        Overall exterior width (a) at the                                                               2462         mm                                             middle portions 10:                                                           Overall exterior width (b) of the end                                                           2438         mm                                             portions 11:                                                                  Overall length (c):                                                                             6058 mm or 12192                                                                           mm                                             Overall thickness (d) of side wall                                                              21.5         mm                                             of middle portion 10:                                                         Minimum internal width (e):                                                                     2419         mm                                             Width (f) of horizontal surface 18 of                                                           21.5         mm                                             platform member:                                                              Overall thickness (g) of corrugated                                                             19.5         mm                                             panelling 19:                                                                 Depth (h) of ribs 32:                                                                           6            mm                                             Length (j) of portions 30 and 31:                                                               90           mm                                             Length (k) of inclined portions 29:                                                             10           mm                                             Thickness (1) of panelling sheet:                                                               about 2      mm                                             Length (m) of end portions 11:                                                                  300          mm approx.                                     Length (n) of inclined interconnecting                                                          65           mm approx.                                     portions 12:                                                                  Overall height (o) of container:                                                                2591         mm                                             Height (p) of surface 18 above                                                                  325          mm                                             bottom of container:                                                          ______________________________________                                    

In FIGS. 3 and 5 various dimensions, for example, the minimum internalwidth (e), are shown which extend across the container and it should beunderstood that those dimensions are the dimensions measured to thecorresponding point (not shown in FIG. 3 or 5) on the opposite side ofthe container. In each case as a result of the symmetry of the containerabout a vertical plane through the longitudinal axis of the containerthe points on each side are equispaced from that vertical plane and theconstruction of the side of the container not shown in FIGS. 3 and 5 isthe mirror image of that shown in FIGS. 3 and 5.

In the example the minimum internal width of 2419 mm applies not only atthe middle portions 10 of the container but also at its end portions 11.If desired, however, the minimum internal width at the end portions 11could be reduced.

When loading pallets into the container the inner surface of the bottomrail member 15 provides a smooth surface of constant cross-section alongthe length of the container and can therefore be used by a fork-lifttruck driver loading a pallet into the container as an abutment surfaceagainst which the pallet can be pressed. It will be appreciated thatsuch a surface is preferable to a corrugated surface which, by virtue ofthe corrugations, varies in cross-section along the length of thecontainer, even though the minimum spacing between the corrugations onopposite sides may be as great. Thus loading of two pallets side-by-sideinto the container with little space between them and the side walls ofthe container is facilitated.

In terms of an overall width of 2438 mm and an overall length of 6058 mmor 12192 mm, an increase in width on each side of the container of 12 mmis not great and even when arrangements are made to place conventionalcontainers side-by-side it is common to allow a small space betweenthem. Thus, the increased lateral projection of 12 mm will not in normalcircumstances prevent such containers being placed in a space intendedfor a container of overall width 2438 mm.

I claim:
 1. A freight container comprising:a pair of opposite ends, apair of opposite sides defining lateral extremities of said containerand extending between said opposite ends of said container, said sideshaving end portions adjacent to said ends and middle portions extendingbetween said end portions, and further having exterior surfaces that arespaced apart by a greater distance along said middle portions than alongsaid end portions which are joined to said ends of the container, saidcontainer thereby having an overall exterior width which is less at saidend portions than at said middle portions, a top, a floor,said ends,sides, top and floor together defining a box of generally cuboidalshape, and a respective corner fitting at each corner of said container,wherein the middle portion of each side comprises a bottom member whichextends both downwardly below said floor and upwardly above said floor,and corrugated panelling disposed above the bottom member, the bottommember defining an upright abutment surface above the floor in theinterior of the container for guiding a pallet being loaded into thecontainer, and wherein the container has an internal width measuredbetween said middle portions of said sides which is more than 2400 mmbut an overall thickness of each of the middle portions of the sidesless than 25 mm and an overall exterior width measured at said middleportions of said sides of less than 2470 mm.
 2. A freight containeraccording to claim 1, in which the overall thickness of each of themiddle portions of the sides is about 20 mm.
 3. A freight containeraccording to claim 1, in which the internal width measured between themiddle portions of the sides is 2419 mm±5 mm.
 4. A freight containeraccording to claim 1, in which the overall exterior width measured atthe middle portions of the sides is 2462 mm±5 mm.
 5. A freight containeraccording to claim 1, in which the middle portion of each side comprisesa bottom rail member, a platform member fixed to the top of the bottomrail member and defining a substantially horizontal surface on top ofthe bottom rail member, and corrugated panelling the corrugated bottomof which is secured to the substantially horizontal surface defined bythe platform member on top of the bottom rail member.
 6. A freightcontainer according to claim 5, in which the platform member is ofinverted, substantially "L" shape with one limb extending downwardlyadjacent to the top of the bottom rail member and the other limbextending substantially horizontally.
 7. A freight container accordingto claim 6, in which the limb of the L-shaped member that extendssubstantially horizontally extends outwardly from the otherdownwardly-extending limb.
 8. A freight container according to claim 6,in which the platform member is formed in an "L" shape by hot rolling.9. A freight container according to claim 5, in which at least onelongitudinally extending rib is formed in the bottom rail member.
 10. Afreight container according to claim 9, in which said at least onelongitudinally extending rib projects outwardly from the bottom railmember.
 11. A freight container according to claim 1, in which theinternal width of the corrugated panelling measured at the middleportions of the sides is substantially the same as the internal widthbetween the abutment surfaces measured at the middle portions of thesides.
 12. A freight container of generally cuboidal shape including apair of sides which define lateral extremities of the container andextend between ends of the container, the exterior surfaces of the pairof sides being spaced apart by a greater distance along their middleportions than along their end portions which are joined to the ends ofthe container, whereby the overall exterior width of the container isless at the end portions than at the middle portions, wherein theinternal width measured between the middle portions of the sides is morethan 2400 mm but the overall thickness of each of the middle portions ofthe sides is less than 25 mm and the overall exterior width measured atthe middle portions of the sides is less than 2470 mm;the middle portionof each side comprising a bottom rail member, a platform member fixed tothe top of the bottom rail member and defining a substantiallyhorizontal surface on top of the bottom rail member, and corrugatedpanelling the corrugated bottom of which is secured to the substantiallyhorizontal surface defined by the platform member on top of the bottomrail member; further including ribs extending parallel to thecorrugations provided in the corrugated panelling.
 13. A freightcontainer according to claim 12, in which the ribs in the corrugationsare contained within the volume defined by the other parts of thecorrugated panelling.
 14. A freight container comprising:pair ofopposite ends, a pair of opposite sides defining lateral extremities ofsaid container and extending between said opposite ends of saidcontainer, said sides having end portions adjacent to said ends andmiddle portions extending between said end portions, and further havingexterior surfaces that are spaced apart by a greater distance along saidmiddle portions than along said end portions which are joined to saidends of the container, said container thereby having an overall exteriorwidth which is less at said end portions than at said middle portions, atop, a floor,said ends, sides, top and floor together defining a box ofgenerally cuboidal shape, and a respective corner fitting at each cornerof said container, wherein the middle portion of each side comprises abottom member which extends both downwardly below said floor andupwardly above said floor, a substantially horizontal surface defined ontop of said bottom member, and corrugated panelling which rests on topof and is secured to said substantially horizontal surface, and whereinthe container has an internal width measured between said middleportions of said sides which is more than 2400 mm but the overallthickness of each of the middle portions of the sides is less than 25 mmand the overall exterior width measured at said middle portions of saidsides is less than 2470 mm and in which the overall exterior width ofthe container measured at the middle portions of the sides is greaterthan the width measured between the exterior surfaces of the bottommember.
 15. A freight container according to claim 14, in which theinternal width of the corrugated panelling measured at the middleportions of the sides is substantially the same as the internal width ofthe bottom member measured at the middle portions of the sides.